[A gradient in the differentiation of the larval tegument of two two cyclophyllid cestoda].

An electron microscopic study of the larval stages of two Cyclophyllid Cestodes, Anomotaenia constricta and Hymenolepis stylosa shows the presence of a morphogenetic field whose center is located in the scolex. This field stimulates the graduated differentiation of the tegument and associated structures from the scolex to the cercomer.